Which Gamma 1.8 /2.2 , PPC vs Macintel

Discussion in 'Design and Graphics' started by basilt, Oct 31, 2016.

  1. basilt macrumors regular


    Aug 15, 2016
    I am still a PPC G5 user but not for long as i bought a macpro 1.1 (2.1) model, used, recently.

    I have a cinema 21" display and use D65, 1.8 gamma for ages.
    I mainly set this gamma for prepress applications and worked ok insofar.

    I do though change my workflow, adding more video to my stock collections, which
    need sRgb space for beter colour space match etc. not sure if 1.8 is adequate for video....

    I recently read that the macpro devices have different Gamma by default if i am not mistaken, 2.2
    and many monitors working with photoshop and web i presume are on sRGB@2.2 gamma.

    I am a bit confused by this and would like to ask your opinions on how you are affected or using
    the gamma and calibrate the monitors ?

    Do you use the 2.2 and why ? Do you also use this gamma for prepress ?

    I will be moving to the macpro soon and i am not sure if is better to copy my ICC profile from the G5
    to the macpro and continue my work as with the G5.
  2. organicCPU macrumors 6502a


    Aug 8, 2016
    The color profile for the cinema 21" you mean? Chances are good that it'd work to transfer and use the file, but a display is aging and colors are changing. Therefore I don't recommend to transfer that for use, but maybe for comparison to a new profile.
    I'd say it makes more sense to generate a recent profile. If you have hardware to calibrate, then that's easy. With no such hardware, use the calibration function in the system preferences -> display and make a new profile just by visual comparisons (there you set the gamma that fits). That'll give you adequate results, too.
    As a cinema display aged for several years and never had the ability to show you full AdobeRGB space, you shouldn't worry too much about precise calibration. If it can show you smaller sRGB, I don't know. If you really want colors to appear as correct as possible, buy a new display first. But even with a calibrated system, that needs to be re-calibrated every several weeks or months, most Windows users usually see an image slightly darker than Mac users and just a few care about their colors. For professional video color grading the cinema display probably won't work. For foreseeable results in cmyk printing with any kind of display, better use printed color reference guides (strips/books).
  3. basilt thread starter macrumors regular


    Aug 15, 2016

    Yeah... I mean the cinema ICC profile from the PPC to move on macpro.
    I use the coloursync to profile the monitor not suction (hardware) calibrators like i.e. eye1 etc.
    And calibrate it with my eye every 2-3 months. so its updated from time to time.

    Cinema is indeed old for sure !
    But what about the Gamma, what reference you would suggest if i make a new profile ? Keep the 1.8 ?

    For video grading you say it should not work that right, but why ? is it due to the aging or profile issue based
    on 1.8 gamma ?

    For CMYK for sure the display does not do the best job as colour space is different, but when i move my cmyk JPG
    files to a prepress beaureau we almost see the same preview on monitor and output is almost similar so i dont get
    huge differences in output. I manly do some i.e. calendars from time to time and thats all in the offset printing sector...
  4. organicCPU macrumors 6502a


    Aug 8, 2016
    Well, If you use the visual calibration method in the monitor system preferences with colorsync in expert mode, the first step lets adjust you the gamma curve. Gamma 1.8 or 2.2 are just standardized curves for the brightness of each value from the dark to the bright tones. Gamma 1.8 or 2.2 probably doesn't fit exactly to your cinema display. But the gamma curve generated in the first step of your profiling does. So why use a standard, if you are getting a much better result from an individual gamma curve?
    As the brightness is fading with the age of your cinema display you can raise the brightness a bit with your Mac's brightness control buttons (Probably Function Key F2). That's what you should do, if you won't get anymore satisfying results in the step 1 of visually setting the gamma curve.
    There are multiple standard color profiles for video editing. One is called Rec. 709 (BT.709). You may need another one. If you open Color Sync Utility you can compare the video editing profile to other profiles and will see how large it is overlapping. That will give you an idea of how much of the actual colors you will see and how much colors you won't see.
    I said, it might not work for professional use in color grading, because I believe, but don't know for sure, that a cinema display can't show all the colors of the video profile you will use. Second, an old display isn't doing better. And to know exactly, what colors are shown, you would need some kind of device to measure that. That doesn't mean there is no chance for you to cut a video with your cinema display and sell it as professional work. It can get complicated, if you visually choose a corporate color that is in the range of those your display can't show and suddenly your pink cow gets brown or other way round. In that cases you'd definitely benefit of a reference display.
    If you can set a special gamma value at your display menu you could set it to 2.2 up to 2.4 or BT.1886. But consider this: What, if your audience like your video color style you did with gamma 1.8 for years and suddenly that style changes? Means, a standard must not give the best result for you! To compare the difference of old and new calibration in context of your work, you might compare an old and a new work once somewhere at a reference display to know what has changed and if you like it. Maybe the MacRumors video forum can give you a better advice for this and especially the 21" cinema display.

    For cmyk, after time you get a good feeling for the results of mixing the colors. It's similar to painting and mixing watercolors. If you trust the values, not the display, you're always on the safe side.
  5. basilt thread starter macrumors regular


    Aug 15, 2016
    thanks again for the reply !

    I will read about the standards you mentioned. Did not know those at all. I thought that all are now
    related with i.e. sRGB and you color grade on any display. But i guess a reference monitor as you point
    is a better solution with video !

    As for the style, this is also true !

    I will also check the video forum !

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